Applications for the water-jet cutting process

Flexible water-jet cutting technology can be used in practically all sectors of industry - an article by Peter Longman, Area Manager, KMT Waterjet Systems. The aerospace, building and construction, mechanical engineering, glass industry, wood, textiles and paper manufacturing sectors are all taking advantage of this versatile process. In addition, the automotive and its supplier industries, as well as the electrical, electronic and food processing and defence industries have all emerged as markets for some of the more novel applications of water-jet.

High-speed prototyping and flexible, just-in-time production are well suited to water-jet whilst new applications including cleaning, recycling and decommissioning.

Unlike traditional thermal cutting methods, water-jet cutting technology has major advantages in terms of its high level of cost-effectiveness and flexibility.

The most diverse materials can be quickly and precisely worked using a high-pressure jet of water.

Material thicknesses of 150 mm or more present no difficulties for this cutting processes.

The water-jet achieves optimum cut-edge qualities on both simple and extremely complex contours.

Water- jet cutting falls into general 2D and 3D applications.

2D include the cutting of sheet metal such as: stainless steel, carbon steel, high-alloy nickel steels, aluminium, titanium and copper.

Construction materials include decorative stone, marble, granite, tiles, plasterboard, glass and mineral wool.

Glass covers: laminated glass, safety glass, and bulletproof glass.

Foodstuffs can range from baked goods to deep-frozen products and fish.

Paper, cardboard, corrugated cardboard, printing papers together with miscellaneous materials such as: plywood, leather, textiles, composites, rubber, plastics, sealing materials and foams are also typical 2D applications.

3D and robot applications cover abrasive cutting of titanium, aluminium and stainless steel motor-vehicle components; turbine blades, decorative stone or marble.

Pure water cutting can be used for motor-vehicle components such as carpets, door-trims, fenders, dashboards, instrument panels, rear shelves.

The essential benefits of the water-jet cutting system are the fact that there are no heat-affected zones, no thermal hardening and no material stresses.

From a health and safety point of view there are also no gases and no production of dust or fumes.

Production benefits include the fact that there is no need to sharpen tools whilst high cutting speeds.

high cutting accuracy and high surface quality can be achieved.

Secondary operations such as deburring can be omitted and re-working becomes unnecessary.

Burr-free cut edges, a narrow cutting gap and low tangential forces exerted on the component also provide user benefits.

Waterjet can be used for both cleaning and removing layers of materials from the surface of products.

KMT’s Streamline pump range can provide high pressure to the Rotojet nozzle so that cleaning can be undertaken in an environmentally friendly way without any gases.

The base material’s integrity is not affected and the process is therefore ideally suited to applications such as jet engine turbine blade decontamination.

As part of the restoration and repair of gas turbine jet engine components undertaken by Wood Group Component Repair, coatings need to be stripped from turbine components prior to re-application.

In order to refine the coating removal process, Wood Group is currently carrying out development work using a KMT waterjet system.

This significantly speeds up the process without affecting the base material.

Hundreds of different coatings are applied to the turbine component parts by plasma arc deposition - mainly on to casings and seal areas where the ceramic or other coating is intended to wear in preference to the mating part.

At present the plasma sprayed coatings are removed by conventional machining, acid bath and grit blasting.

This is a very time consuming operation and some of the base material is removed during the operation.

These problems are eliminated by the waterjet process comprising of a Streamline SL IV 50Hp pump that produces 3,800bar (55,000psi) working pressure.